The present invention relates to methods for providing a dry environment for underwater repair of reactor bottom heads in a restrictive access environment.
There is an emerging need for effecting weld repairs at the bottom head of boiling water reactors. For example stub tubes, incore housing penetrations, pressure lines penetrations and cladding surface repair along the bottom head of the nuclear reactor vessel often require weld repairs. Generally, such weld head repairs have been effected subsequent to draining the nuclear reactor vessel in order to provide a dry environment for welding. Accordingly, there is a need for a method of effecting weld repairs and inspections at the bottom head of nuclear reactor vessels in a totally dry environment and without draining the reactor vessel.